High-lift performance is a key objective in aircraft design and may be represented by the performance of the aircraft during takeoff and/or landing. An aircraft with improved high-lift performance may have a relatively high maximum takeoff weight for a given runway length. Alternatively, an aircraft with improved high-lift performance may require a reduced runway length for a given maximum takeoff weight. Other advantages provided by high-lift performance include reduced stall speed and/or increased range. The high-lift performance of an aircraft may be provided by one or more types of high-lift systems or devices. For example, the wings of an aircraft may include leading edge slats and/or trailing edge flaps which may be deployed during takeoff and landing to increase lift.
High-lift devices preferably generate a relatively small amount of aerodynamic drag when deployed so that the aircraft has a high lift-to-drag ratio (L/D). A high L/D may result in increased payload capacity, reduced runway length requirements, and/or longer range for the aircraft. For example, for a twin-engine transport aircraft, a 1% increase in L/D during takeoff may result in an increase in payload capacity of up to several thousand pounds or an increase in range of up to 150 nautical miles. In addition, an increase in L/D during takeoff may allow for a reduction in engine size which may translate directly to a reduction in the structural mass of the aircraft and an improvement in fuel efficiency and/or a reduction in engine emissions. High-lift devices also preferably increase the maximum lift coefficient (CLmax) of the aircraft which can result in a significant improvement in the high-lift performance of the aircraft. For example, a 1.5% increase in CLmax for an example transport aircraft may result in an increase in payload capacity of up to 6600 pounds for a fixed approach speed.
Conventional methods for improving the L/D and the CLmax of an aircraft rely on the adjustment of a high-lift system within the geometrical constraints of the wings. For example, the geometry and deployment characteristics of leading edge slats and trailing edge flaps may be adjusted in an attempt to improve the L/D and CLmax at takeoff and landing. Unfortunately, the adjustment of the geometry and deployment characteristics of such high-lift devices represents a limitation to high-lift performance.
As can be seen, there exists a need in the art for a system and method for improving the high-lift performance of an aircraft that is not limited by the geometrical constraints of the wings and/or high-lift devices.